gardella



Feb. 24, 1931. w GARDELLA 1,793,688

PRES S ROLL Filed April 17. 1950 .7 "W n" 5 l /i L 4 4 6 6 K 7 4 I l2 l3 -FIG. 4 6

FIG. 3

INVENTOR.

ATTORNEYS.

Patented Feb. 24, 1931 1 UNITED STATES PATENT OFFICE WILLIAM H. GARDELLA, OF FLUSHING, NEW YORK, ASSIGNOR TO OLIVER UNITED FILTERS INC., OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF NEVADA' PRESS ROLL Application filed April 17, 1930. Serial No. 444,929.

This invention relates to press rolls, and I particularly to press rolls used in conjunction with paper machinery and continuous filters.

In various stages of the manufacture of paper, the stock used has to be washed and/or thickened and oftentimes continuous filters are used for this purpose and when so used are called thickeners or deckers. One of the greatest difliculties experienced in connection with the use of this type of filter is in expressing the water contained in the cake formed on the filter surface.

Many forms of press rolls have been tried, all of which are adapted to contact with the water logged material to express the water therefrom but in most cases it has been found that the water expressed from the line of contact between the press rolls and the material under treatment is re-absorbed by thev material immediately on either side of such line of contact.

In general, then, the object of my invention is the provision of a press roll adapted to be used in connection with filter and paper machinery which will not only express the water contained in the material being treated but which will entrap the expressed water and convey it away from that portion of the material which has already been pressed.

More specifically, the object of my invention is the provision of a perforated cylindrical press roll provided with valves in registration with its perforations which are adapted to be opened by the relative pressure between the roll and the material under treatment.

The invention possesses other advantageous features, some of which with the foregoing, will be set forth at length in the following description where I shall outline in full that form of my invention which I have selected for illustration in the drawings accompanying and forming part of the present specification. In said drawings, I have shown one form of my. invention, but it is to be understood that I do not limit myself to such form, since the invention as set forth in the claims, may be embodied in a plurality of. forms.

Referring to the drawings:

Figure 1 is a perspective view of a press roll embodying the objects of my invention and shown in its operative position with respect to a continuous rotary drum filter.

Figure 2 is a vertical section taken on the lines 22 of the roll shown in Figure 1.

Figure 3 is an enlarged section taken on the line 33 of Figure 2 showing one of the valves in its open position.

Figure 4 is a section showing one of the valves in its closed position.

Figure 5 is a fragmentary plan View of a valved rubber strip.

Figure 6 is a vertical section taken on the line 6 6 of Figure 5 and showing the flanges carried on the under-side of the strip adapted to be accommodated in the perforations of the cylindrical roll for maintaining the valves in registration with the perforations.

The objects of my invention may be conveniently embodied in a cylinder 1 provided at its end with bearings 2 adapted to accommodate a shaft 3. The cylinder is provided with a plurality of perforations 4 which are preferably countersunkat their outer ends as at 5. The surface of the cylinder is covered cured in any suitable manner over the rubber sheet or sleeve 6.

In Figure 1 is shown the relative position that a press roll of this character occupies in relation to the surface of a rotary drum filter and it is to be noted that the roll is mounted substantially below the Zenith of the'filter. Although not shown, it'is to be understood thatthe press roll is mounted by means of the shaft 3 in suitable brackets carried by the frame of the filter or paper machine, as'the case may be. Prefera ly the roll is mounted in spring pressed arms or is counterweighted so that its pressure on the material under treatment is adjustable and substantially constant. Normally press rolls are driven by frictional contact with the cake or material under treatment and this roll may be driven in the same manner, or if desired it may be positively driven by any well known mechanism. 7

The operation of the press roll embodying the object of my invention is as follows:

If the roll is used in conjunction with a continuous rotary drum filter, it is mounted as shown in Figure 1 and exerts a pre-determined pressure on the cake picked up by the filter. The pressure of the roll on the cake expresses a large portion of its liquid content and momentarily opens the valves 7 thereby entrapping the expressed liquid within the roll.

The valves 7 are open only during their contact with the cake for the natural resiliency of the leaves 11, 12 and 13 together with the action of gravity and the weight of the liquid contained within the roll serve to close them as soon as they have passed out of contact with the cake. As already explained, the screen 8 serves to prevent the valves 7 from opening outwardly. The liquid entering the roll through the valve and entrapped therein escapes from either end of the roll to the filter tank or to any other suitable container that may be furnished for that purpose.

Although the simplest way of valving the perforations 4 in the cylinder 1 seems to be 3 provided with intersecting cups as described, there are other ways of accomplishing the same purpose, as for example that shown in Figures 5 and 6. The structure shown in these figures consists of a strip of sheet rubber substantially the length of the press roll upon which. it is to be used and provided on its lower surface with a plurality of flanges 15 adapted to be accommodated in the perforations of the cylinder. As shown, valves are formed within the area circumscribed by the flanges 15. These strips are designed to be placed longitudinally over the surface of the cylinder and to completely cover its surface and may be secured thereto in any well known manner.

Another method which may be used to valve the perforations in the cylinder is to provide unitary cup shaped members provided at one end with valves similar to those shown in the modifications already described.

By the above description I have disclosed a press roll which not only serves to press or squeeze the water from the cake or material under treatment but which furthermore traps the liquid so expressed and carrles it away the use of a continuous sheet of rubber from that portion of the material already treated.

As above stated, this roll is also adapted to be used in connection with paper making machinery other than filters where the results desired to be accomplished are similar.

I claim:

1. A cylindrical press roll provided on its exterior surface with a plurality of inwardly opening valves.

2. A cylindrical press roll provided on its surface with a plurality of inwardly opening pressure responsive valves.

3. A press roll comprising a cylinder having a plurality of perforations over its sur face and inwardly opening valves in registration with said perforations.

4; A press roll comprising a cylinder provided with a plurality of perforations over its surface, inwardly opening valves in registration with said perforations and means for preventing said valves from opening outwardly.

5. A press roll comprising a-cylinder provided with a plurality of perforations, valves in registration with said perforations and a screen covering said cylinder and preventing said valves from opening outwardly.

6. A press roll comprising a cylinder pro vided with a plurality of perforations, a rubber covering secured to said cylinder and provided with valves in registration with said perforations and a wire mesh screen secured over said rubber covering for preventing said valves from opening outwardly.

In testimony whereof, I have hereunto set my hand.

WILLIAM M. GARDELLA. 

